20.
Front Board (Key Slip) Warped on a Piano

Just in front of the keys is a vertical board two to three inches high,
by three quarters of an inch wide, which runs all the way from left to right.
This board can warp, especially on new pianos and during damp weather. The way
you can tell if it is a problem is that certain natural (white) keys will hang
up. Before dismantling the piano to find the problem, check the Key Slip, which
is the professional term for this board.

Diagnosis:

Make sure the front board is truly the problem. Hang your thumb on the
top of it and pull outward. Strike the key hanging up. If it stops sticking,
push in (toward the keys) on the board. Strike the key again, and if it sticks
bad, you have found the problem. Check the Diagram
page if you are not sure where the "Front Board" is.

To repair
it:

On all uprights, remove the screws right under it, and set it aside. On
grands, there are several ways the key slip comes out. Some simply lift straight
up off of grooves in the wood which catch on screws sticking out. Most grand
key slips come off by removing screws underneath, just like upright pianos.

Find some poster board to make shims. Cut them about a half inch wide and
an inch long. You want to make the board look even, so shim it at about one
third and one third along the board, or at quarter points along the board if
it is really warped badly..

Stack up two shims, and gum them in place with something sticky-- Mr. PK
Wrigley invented a very good product for this-- chewing gum. Glue the shims
(two sets) standing against the front edge of the key bed (Check the Diagram
page again)-- That is the board right behind the key slip.

Exception-- Some well made pianos, like Kawai, have screws coming out of
the key bed to meet the back of the key slip. There are usually only two. Unscrew
these about one half turn each, and reassemble. That should take care
of it.

Replace the key slip, and screw it tight. Try the test again. If the key
doesn't stick, play a two part invention and go have a cup of tea. If it still
sticks, repeat the process, but this time add shims between the end blocks and
the key slip, on either end, to keep the board from warping badly. You may add
a piece of scarlet felt between the end blocks and the key slip so that is shows
somewhat. This does the job there, and it adds a nice touch. Some piano makers
did this anyway on new pianos.